Ozai was the ruler of the Fire Nation during the final years of the Hundred Year War, reigning as Fire Lord he was the second son of Fire Lord Azulon and Ilah, the younger brother of Iroh, uncle of Lu Ten, husband to Ursa, the father of Prince Zuko and Princess Azula, and the paternal grandfather of Izumi Ozai was a firebending master and, prior to the end of the war, was the most powerful firebender in the world.